CN218567091U

CN218567091U - Shaft concrete temperature stress testing machine

Info

Publication number: CN218567091U
Application number: CN202222838554.1U
Authority: CN
Inventors: 李辉; 陈鋆; 许红星
Original assignee: Zhejiang Shengke Technology Co ltd
Current assignee: Zhejiang Shengke Technology Co ltd
Priority date: 2022-10-26
Filing date: 2022-10-26
Publication date: 2023-03-03
Anticipated expiration: 2032-10-26

Abstract

The utility model relates to a temperature stress test technical field discloses a pit shaft concrete temperature stress test machine, include: the top is equipped with opening and inside be equipped with accommodation space the frame, be used for supporting the test piece and with frame sliding connection's supporting seat, the expansion end and the stiff end that set up relatively, be used for driving the expansion end orientation or keep away from drive division, setting that the stiff end removed are on the test piece or on expansion end and the stiff end for acquire the displacement detection subassembly of the change volume of test piece and be used for acquireing the force transducer because of the power that test piece inflation or shrink produced. Based on the fact that the displacement detection assembly is arranged on the test piece or the movable end and the fixed end, deformation data generated by the frame cannot be calculated in a deformation range of the test piece during data detection. Based on supporting seat and frame be sliding connection, reduced the frictional force between test piece and the frame greatly, the degree of accuracy of test data obtains improving.

Description

Shaft concrete temperature stress testing machine

Technical Field

The utility model relates to a temperature stress test field specifically relates to a pit shaft concrete temperature stress test machine.

Background

The problem of concrete cracking is always difficult to solve, and the durability of a concrete structure is greatly influenced by corrosion of internal steel bars due to cracking. The problem of cracking must be overcome if a reinforced concrete structure is to be made durable. In practical engineering, the prior art has difficulty in securely avoiding the occurrence of concrete cracking, which is determined by the inherent material characteristics of concrete. To avoid cracking from the viewpoint of improving the cracking resistance of concrete, it is necessary to start with controlling the tensile stress. It is relatively easy to control the tensile stress compared to increasing the tensile strength.

One of the factors determining the magnitude of the tensile stress is deformation, and generally, the concrete deformation types include temperature deformation, self-shrinkage, and drying shrinkage, and when an expanding agent is added, expansion and shrinkage are also caused. The investigation methods for the temperature stress test generally include the following three:

(1) And (3) constraint stress measurement: when the deformation (expansion or contraction) of the test piece reaches a certain limit value (5-10 μm), the computer controls the servo motor to force the test piece to displace, so that the deformation value is kept about 0, and the motor stops running.

(2) Free deformation measurement: when the constraint stress (tensile stress or compressive stress) on the test piece reaches a certain limit value of +/-0.01 MPa, the computer controls the servo motor to forcibly adjust the deformation of the test piece, so that the stress value is kept at about 0, and the motor stops running.

(3) And (3) measuring the elastic modulus: and applying a certain load to the concrete in a short time, and measuring the deformation of the test piece in the process.

In the prior art, since the displacement detection assembly is mounted on the frame, the deformation of the frame is calculated in the test result, which affects the accuracy of the data. In addition, the test piece and the frame are in contact, and when the test piece deforms, the friction force generated between the test piece and the frame also influences the accuracy of test data.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a pit shaft concrete temperature stress test machine to among the solution prior art, displacement sensor's mounted position and the arrangement of test piece are to the influence of test data.

In order to realize the above-mentioned purpose, the utility model provides a pit shaft concrete temperature stress test machine, including the top be equipped with opening and inside be equipped with accommodation space the frame, be used for supporting the test piece and with frame sliding connection's supporting seat, the expansion end and the stiff end that set up relatively, be used for the drive the expansion end orientation or keep away from the drive division that the stiff end removed, setting on the test piece or on expansion end and the fixed end for acquire the displacement detection subassembly of the change volume of test piece and be used for acquireing the force sensor because of the test piece inflation or the power that the shrink produced.

Through the technical scheme, the displacement detection assembly is arranged on the test piece or the movable end and the fixed end, and when data are detected, deformation data generated by the frame cannot be calculated in the deformation range of the test piece. Based on supporting seat and frame be sliding connection, the frictional force between test piece and the frame has reduced greatly, and the degree of accuracy of test data obtains improving.

Further, the displacement detection assembly comprises a first fixed plate arranged on the fixed end, a second fixed plate arranged on the movable end and opposite to the first fixed plate, a connecting plate with one end connected to the second fixed plate and the other end extending to a position close to the first fixed plate, and a displacement sensor;

the displacement sensor is arranged at the other end, connected with the second fixing plate, of the connecting plate and abuts against one side end face, facing the second fixing plate, of the first fixing plate.

Further, the displacement detection assembly comprises a first fixing plate arranged at one end of the test piece, a second fixing plate arranged opposite to the first fixing plate and positioned at the other end of the test piece, a connecting plate with one end connected to the second fixing plate and the other end extending to a position close to the first fixing plate, and a displacement sensor;

Further, the displacement sensor is an LVDT displacement sensor.

Further, the force sensor is a spoke type tension and pressure sensor.

Furthermore, a sliding rail is arranged on the upper end face of the bottom of the frame, and the supporting seat is connected with the sliding rail in a sliding mode in the driving direction of the driving portion.

Further, the driving part comprises a ball screw, a speed reducer, a servo motor and a screw nut; the output end of the speed reducer is connected with the ball screw through a coupling; the servo motor is directly connected with the input end of the speed reducer; the screw nut is sleeved on the ball screw and is fixedly connected with the movable end.

Further, a sleeve is sleeved outside the screw nut, and the force sensor is fixedly arranged at one end, facing the movable end, of the sleeve; the movable end and the force sensor are coaxially arranged.

Further, the shaft concrete temperature stress testing machine also comprises a controller; the force sensor and the displacement sensor are electrically connected with the controller.

Further, the test piece comprises a model and a mold which is wrapped outside the model and is detachably connected with the model; and a temperature waterway pipeline for adjusting the model is arranged between the mold and the model.

Other features and advantages of the present invention will be described in detail in the detailed description which follows.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the temperature stress testing machine of the present invention;

FIG. 2 is an enlarged view of portion A of FIG. 1;

FIG. 3 is a partial schematic view of the driving part;

fig. 4 is an enlarged view of a portion B in fig. 1.

Detailed Description

The following describes the embodiments of the present invention in detail. It should be understood that the description herein is provided for illustration and explanation of the invention and is not intended to limit the invention.

In the present invention, the use of the terms of orientation such as "upper and lower" in the case where no description is made to the contrary generally means the orientation in the assembled and used state. "inner and outer" refer to the inner and outer contours of the components themselves.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged under appropriate circumstances for purposes of describing the embodiments of the invention herein. Moreover, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The utility model provides a pit shaft concrete temperature stress testing machine, as shown in figure 1 and figure 2, this testing machine includes frame 10, supporting seat 20, expansion end 31, stiff end 38, displacement detection subassembly and force sensor. The frame 10 is formed as a frame structure having an opening at the upper side and an accommodating space inside. The lifting device comprises a bottom plate, vertical plates vertically arranged at two ends of the bottom plate and a cross rod connected with the two vertical plates.

The supporting seat 20 is used for supporting the test piece 100, and makes the test piece 100 overhead to counteract the gravity applied to the test piece 100. Meanwhile, the support base 20 is slidably coupled to the bottom of the frame 10. Such an arrangement may reduce the friction between the test piece 100 and the bottom of the frame 10, and minimize errors in the test data.

The support base 20 and the sliding arrangement of the support base 20 and the bottom of the frame 10 are one of the innovations of the present invention. In the prior art, the test piece 100 is placed directly on the ground or on the upper end of the bottom of the frame. The prior art has the following disadvantages: the friction force between the test piece 100 and the ground or the frame hinders the actual deformation degree of the test piece 100 to a certain extent, and the tensile stress generated by the deformation of the test piece 100 is increased, so that the data obtained by the test has larger deviation. And in the technical scheme of the utility model, because test piece 100 receives the support of supporting seat, supporting seat 20 is sliding connection with frame 10 simultaneously, can reduce test piece 100 like this greatly and at the deformation in-process, the frictional force that produces between test piece 100 and ground or the frame reduces the data error to the influence of test data. At the same time, due to the arrangement of the supporting seat 20, the gravity force applied to the test piece 100 is counteracted, that is, the force sensor will only be subjected to tensile stress in the transverse direction (axial direction), and the interference of the gravity force applied to the test piece 100 in the vertical direction to the pressure force applied to the force sensor in the transverse direction is eliminated.

The movable end 31 and the fixed end 38 are disposed opposite to each other. Wherein the fixed end 38 is fixedly connected with the frame 10. The movable end 31 is fixedly connected with the telescopic end of the driving part 30, and the driving part 30 is used for driving the movable end 31 to move towards or away from the fixed end. In practical tests, the two ends of the test piece 100 are fixedly connected with the movable end 31 and the fixed end 38 respectively. The means of fixed connection may be by clamps or fasteners such as bolts and flanges. After the test is complete, the test piece 100 is removed by loosening the clamps or touch fasteners.

The displacement detecting assembly is disposed on the specimen 100 or on the movable end 31 and the fixed end 38 for acquiring the deformation amount of the specimen. The arrangement mode of the displacement detection assembly is also one of the innovations of the utility model relative to the prior art. In the prior art, the displacement detecting assembly is provided on the frame. Such an arrangement may be referred to as a combination of the deformation amount of the frame and the deformation amount of the test piece. That is, the displacement amount acquired by the displacement detecting unit includes both the deformation amount of the frame and the deformation amount of the test piece. Such test data is inaccurate. When the displacement detecting assemblies are arranged on the test piece or the movable end 31 and the fixed end 38, the deformation amount obtained by the displacement detecting assemblies is only the deformation amount of the test piece 100, and the data result is more accurate.

The force sensor is used to acquire the force generated by the expansion or contraction of the specimen 100 at the active end. In an alternative embodiment, the force sensor is a spoke-type tension-pressure sensor. The range is 300kN, the straightness 0.03% FS.

With the above technical solution, based on the fact that the displacement detecting components are disposed on the specimen 100 or on the movable end 31 and the fixed end 38, the deformation data generated by the frame is not calculated within the deformation range of the specimen 100 when detecting the data. Based on the supporting seat 20 and the sliding connection between the supporting seat 20 and the frame 10, the friction force between the test piece 100 and the frame 10 or the ground is greatly reduced, the influence of the friction force on test data is greatly reduced, and the accuracy of the test data is obviously improved.

In an alternative embodiment, the displacement detecting assembly includes a first fixing plate 41, a second fixing plate 42, a connecting plate 43, and a displacement sensor 44. The first fixing plate 41 is disposed on the fixing end 38. The second fixing plate 42 is disposed on the movable end 31 and opposite to the first fixing plate 41. One end of the connecting plate 43 is connected to the second fixing plate 42, and the other end extends to be close to the first fixing plate 41. The displacement sensor 44 is disposed at the other end of the connecting plate 43 connected to the second fixing plate 42 and abuts against the end surface of the first fixing plate 41 on the side facing the second fixing plate 42. Preferably, the displacement sensor 44 is an LVDT displacement sensor with a measurement range of + -500 μm and a precision of 0.1-0.5 μm.

In another alternative embodiment, the displacement detecting assembly includes a first fixing plate 41, a second fixing plate 42, a connecting plate 43, and a displacement sensor 44. The first fixing plate 41 is disposed on one end of the test piece 100. The second fixing plate 42 is disposed opposite to the first fixing plate 41 and at the other end of the test piece 100. One end of the connecting plate 43 is connected to the second fixing plate 42, and the other end extends to be close to the first fixing plate 41. The displacement sensor 44 is disposed at the other end of the connecting plate 43 connected to the second fixing plate 42 and abuts against the end face of the first fixing plate 41 on the side facing the second fixing plate 42. Preferably, the displacement sensor 44 is an LVDT displacement sensor with a measurement range of + -500 μm and a precision of 0.1-0.5 μm.

In the two embodiments, the displacement sensor 44 is disposed at the other end of the connecting plate 43 connected to the second fixing plate 42 and abuts against the end surface of the first fixing plate 41 facing the second fixing plate 42, that is, the head of the LVDT displacement sensor abuts against the end surface of the second fixing plate 42 and has a certain amount of compression. When the test piece 100 expands, the distance between the first fixing plate 41 and the second fixing plate 42 becomes larger, and the amount of compression of the LVDT displacement sensor becomes smaller, but the LVDT displacement sensor does not leave the second fixing plate 42 but remains in interference with the second fixing plate 42. The difference between the compression before and after the LVDT displacement sensor is the deformation of the test piece 100 in the axial direction.

As shown in fig. 1, in the foregoing, the sliding connection between the test piece 100 and the frame 10 can be achieved by the following technical solutions: the upper end surface of the bottom of the frame 10 is provided with a slide rail 50, and the support base 20 is slidably connected to the slide rail 50 in the driving direction of the driving part 30.

In an alternative embodiment, the driving portion 30 includes a ball screw 36, a reducer, a servo motor, and a screw nut 35. The output end of the speed reducer is connected with the ball screw 36 through a coupling. The servo motor is directly connected with the input end of the speed reducer and is used for driving the ball screw 36 to rotate. The loading speed of the servo motor is 0.01-20mm/min. The ball screw 36 is sleeved with a screw nut 35, which is fixedly connected with the movable end 31. The ball screw 36 is driven to rotate by the servo motor, so that the screw nut 35 is driven to move back and forth along the length direction of the ball screw 36, so that the movable end 31 can be close to or away from the fixed end 38.

As shown in fig. 3, a sleeve 32 is provided outside the lead screw nut sleeve, and a force sensor 33 is fixedly provided at one end of the sleeve 32 facing the movable end 31. The free end 31 is arranged coaxially with the force sensor 33. The sleeve 32 is connected to a lead screw nut 35 by a fastener 34 (e.g., a screw). As shown in fig. 4, the movable end 31 and the force sensor 33 may be removably connected by a connector 37. More specifically, a fixed flange is provided at the center of one end of the movable end 31 facing the force sensor 33, one end of the connector is fixedly connected to the flange, and the other end is fixedly connected to the force sensor 33. Through such setting, can guarantee to guarantee ball 36's atress along its axial, improve the degree of accuracy of test data. In an alternative embodiment, the connector is a cylinder connector.

In addition, the shaft concrete temperature stress testing machine further comprises a controller; the force sensor and the displacement sensor 44 are both electrically connected to the controller.

The test piece 100 comprises a model and a mold which is wrapped outside the model and is detachably connected with the model; and a temperature waterway pipeline for adjusting the model is arranged between the mold and the model. Based on the setting of water route pipeline, can realize the temperature of artificial control test piece 100, provide abundanter test data for the experiment.

In actual use, the two ends of the test piece 100 are fixed to the movable end 31 and the fixed end 38, respectively. The supporting seat 20 is used for supporting the test piece 100 to counteract the gravity borne by the test piece 100, so that the stress of the test piece 100 and the stress of the lead screw are ensured to be axial, and meanwhile, the pressure data obtained by the force sensor is also axial force. Through the configuration mode, the test data can be more accurate.

The support base 20 is slidably coupled to the bottom of the frame 10 by a slide rail 50. The displacement sensing assemblies are mounted on the test piece 100 or the movable end 31 and the fixed end 38 to acquire the amount of expansion or contraction of the test piece 100. The force sensor is used to acquire the force generated by the expansion or contraction of the test piece 100.

The above detailed description describes the preferred embodiments of the present invention, but the present invention is not limited to the details of the above embodiments, and the technical idea of the present invention can be within the scope of the present invention, and can be right to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, the present invention does not separately describe various possible combinations.

In addition, various embodiments of the present invention can be arbitrarily combined with each other, and the disclosed content of the present invention should be considered as the same as long as it does not violate the idea of the present invention.

Claims

1. The utility model provides a pit shaft concrete temperature stress test machine, its characterized in that, pit shaft concrete temperature stress test machine include the top be equipped with opening and inside be equipped with accommodation space frame (10), be used for supporting test piece (100) and with frame (10) sliding connection's supporting seat (20), relative expansion end (31) and stiff end (38) that set up, be used for the drive expansion end (31) orientation or keep away from drive division (30) that the stiff end removed, set up on test piece (100) or on expansion end (31) and stiff end (38), be used for acquireing the displacement detection subassembly of the change volume of test piece (100) and be used for acquireing the force sensor because of the power that test piece (100) inflation or shrink produced.

2. The shaft concrete temperature stress testing machine according to claim 1, wherein the displacement detecting assembly comprises a first fixing plate (41) arranged on the fixed end (38), a second fixing plate (42) arranged on the movable end (31) and opposite to the first fixing plate (41), a connecting plate (43) with one end connected to the second fixing plate (42) and the other end extending to be close to the first fixing plate (41), and a displacement sensor (44);

the displacement sensor (44) is arranged at the other end of the connecting plate (43) connected with the second fixing plate (42) and abuts against one side end face, facing the second fixing plate (42), of the first fixing plate (41).

3. The shaft concrete temperature stress testing machine according to claim 1, characterized in that the displacement detection assembly comprises a first fixing plate (41) arranged on one end of the test piece (100), a second fixing plate (42) arranged opposite to the first fixing plate (41) and located at the other end of the test piece (100), a connecting plate (43) with one end connected to the second fixing plate (42) and the other end extending to be close to the first fixing plate (41), and a displacement sensor (44);

4. A wellbore concrete temperature stress testing machine according to claim 2, characterized in that the displacement sensor (44) is an LVDT displacement sensor.

5. A shaft concrete temperature stress tester according to claim 3, characterized in that the displacement sensor (44) is an LVDT displacement sensor.

6. The wellbore concrete temperature stress tester of claim 1, wherein the force sensor is a spoke-type tension-pressure sensor.

7. Shaft concrete temperature stress testing machine according to claim 1, characterized in that the frame (10) is provided with a sliding rail (50) on the upper end face of the bottom, and the support base (20) is connected with the sliding rail (50) in a sliding manner in the driving direction of the driving part (30).

8. The shaft concrete temperature stress testing machine according to claim 1, wherein the driving portion (30) comprises a ball screw (36), a reducer, a servo motor, and a screw nut (35); the output end of the speed reducer is connected with the ball screw through a coupler; the servo motor is directly connected with the input end of the speed reducer; the screw nut is sleeved on the ball screw and fixedly connected with the movable end (31).

9. The shaft concrete temperature stress testing machine according to claim 8, characterized in that a sleeve (32) is sleeved outside the lead screw nut (35), and the force sensor (33) is fixedly arranged at one end of the sleeve (32) facing the movable end (31); the movable end (31) and the force sensor (33) are coaxially arranged.

10. The wellbore concrete temperature stress tester of any one of claims 2-5, wherein the wellbore concrete temperature stress tester further comprises a controller; the force sensor and the displacement sensor (44) are both electrically connected to the controller.

11. The wellbore concrete temperature stress testing machine of claim 1, wherein the test piece (100) comprises a model and a mold which is wrapped outside the model and detachably connected with the model; and a temperature waterway pipeline for adjusting the model is arranged between the mold and the model.